acer z520 need cdc driver to unlock

team i need your help i try to unlock this model but the box ask cdc driver i try to download from support area but the driver is not the exact driver the phone required i cant unlock the phone pls send me exact driver

heres the logs

Selected connection metod: META Mode
Exe version: NCKBox AndroidMTK
Selected phone: Acer Z520
Scanning for presents meta ports…
Meta ports not detected, starting brom stage.
Curent Platform: MT6582
Phone must be off with battery inside.
Please insert USB cable now…
Detected(9) : PreLoader USB VCOM Port (COM9)
Starting META mode, wait…
Restarting, wait….
Restarting to meta,wait….
If drivers missing, please install CDC drivers.
This can take up to 5 min on slow phones.
If take too long, check device manager for drivers.